1. Field of the Invention
The present invention relates to a helmet used by a motorcycle rider and the like, and particularly to a full-face type helmet including a chin-covering portion provided on a cap body to define a space for breathing of a user, while forming a lower portion under a window in a front face of the cap body.
2. Description of the Related Art
When such a full-face type helmet is used with the window covered by a shield plate, an inner surface of the shield plate is liable to be fogged by the breath exhaled by the user, particularly in a winter season in which there is a large difference in temperature between the inside and outside of the shield plate. The following helmets designed to overcome such fogging have been conventionally known:
(1) A helmet in which a mask made of an elastic material for covering the user""s nose and mouth is mounted on an inner wall of a chin-covering portion by a fastener, and a breathing bore is provided in a lower portion of the mask to permit the inside of the mask to communicate with an area below the chin-covering portion, and guide the user""s breath to below the chin-covering portion by the mask, thereby preventing the fogging of the inner surface of the shield plate (see Japanese Utility Model Publication No. 1-39690).
(2) A helmet in which discharge bores are provided in left and right sidewalls of a chin-covering portion, so that a negative pressure or vacuum is generated in the discharge bores by travel wind flowing on an outer surface of the chin-covering portion, whereby the user""s breath is drawn through the discharge bores to the outside to prevent an inner surface of a shield plate from being fogged (see Japanese Utility Model Publication No. 2-87029).
In the helmet described in the item (1), the mask having a special structure is required, so that an increase in cost is unavoidable. In the helmet described in the item (2), the strength of a shell of the chin-covering portion is deteriorated to some extent due to the discharge bores.
Accordingly, it is an object of the present invention to provide a full-face type helmet for vehicular users, which is of a simplified structure and which is designed so that the strength of the chin-covering portion cannot be deteriorated, and the user""s breath is drawn effectively to below the chin-covering portion to prevent the inner surface of the shield plate from being fogged.
To achieve the above object, according to a first aspect and feature of the present invention, there is provided a full-face type helmet for vehicular users, comprising a chin-covering portion provided on a cap body to define a space for breathing of a user, while forming a lower portion under a window in a front face of the cap body, wherein the chin-covering portion includes a lower end edge which is formed to be directed upwards in a backward direction on wearing position of the cap body, and bulges formed at left and right outer surfaces of the chin-covering portion to be continuous to the lower end edge, so that travel wind is passed on outer surfaces of the bulges to traverse the lower end edge, thereby generating a negative pressure or vacuum at a lower portion of the chin-covering portion.
With the above arrangement of the first feature, if a user drives a vehicle to travel with the cap body put on his head, the travel wind passed on the bulges formed at the left and right outer surfaces of the chin-covering portion traverses the lower end edge of the chin-covering portion, whereby a negative pressure or vacuum is generated in the vicinity of the lower end edge behind the bulges. Thus, the user""s breath in the breathing space can be drawn effectively to below the chin-covering portion, thereby preventing the fogging of an inner surface of a shield plate due to the breath. Moreover, it is unnecessary to attach a mask of a special structure to the chin-covering portion and to provide a discharge bore in the chin-covering portion as in the prior art helmet. Therefore, the chin-covering portion has a simple structure, and suffers no reduction in strength of the chin-covering portion.
According to a second aspect and feature of the present invention, in addition to the first feature, the chin-covering potion has breath-discharge recesses provided in its inner surface at locations corresponding to the bulges to open at the lower portion of the chin-covering portion.
With the above arrangement of the second feature, the breath-discharge recesses are located in the vicinity of the bulges where a negative pressure or vacuum is generated. Therefore, the negative pressure or vacuum is applied well to the recesses, whereby the breath draw-out effect can be enhanced.
According to a third aspect and feature of the present invention, in addition to the first or second feature, the bulges are formed by outwardly bulging a lower end of a shell of the chin-covering portion.
With the arrangement of the third feature, the breath-discharge recesses can be formed on the inner surface of the chin-covering portion as deeply as the lower end of the shell of the chin-covering portion bulges outwards, whereby the breath draw-out effect can be further enhanced.
Further, according to a fourth aspect and feature of the present invention, in addition to the first or second feature, the bulges are integrally formed on an outer surface of a beading member mounted to a peripheral edge of a lower end of a shell of the cap body.
With the arrangement of the fourth feature, since the bulges can be formed simultaneously with the formation of the beading member, the formation of the bulges is facilitated.
Yet further, according to a fifth aspect and feature of the present invention, in addition to the first or second feature, the chin-covering portion has a protruding wall formed on its inner surface to extend along the lower portion under the window, and a baffle plate for inhibiting the ascending of the user""s breath is mounted on the protruding wall to protrude downwards.
With the arrangement of the fifth feature, the downward discharge of the breath in the breathing space can be promoted to increase the effect of preventing the fogging of an inner surface of a shield plate.
According to a sixth aspect and feature of the present invention, in addition to the fifth feature, the full-face type helmet further comprises a breath-discharge plate disposed in the chin-covering portion, the breath-discharge plate including: a louver extending forwards from a lower end of the baffle plate to define a horizontal passage between the louver itself and a lower surface of the projecting wall and having a plurality of ventilating bores; a guide plate bent downwards from a front end of the louver along an inner surface of the chin-covering portion; and a pair of left and right discharge passages defined in left and right opposite ends of the guide plate to permit the passage to communicate with the breath-discharge recesses.
With the arrangement of the sixth feature, when a negative pressure generated behind the bulges at left and right outer surfaces of the chin-covering portion due to the travel wind passing on the bulges, acts on the breath-discharge recesses in left and right inner surfaces of the chin-covering portion, the negative pressure is passed through the discharge passages and the horizontal passage, to act on the louver. Therefore, the breath of a user is passed through a plurality of ventilating bores in the louver into the passage by the draw-in effect of the negative pressure, and flows smoothly to the outside through the left and right discharge passages and the left and right recesses. As a result, the discharge of the breath to below the chin-covering portion can be promoted more effectively to increase the effect of preventing the fogging of an inner surface of a shield plate.
The above and other objects, features and advantages of the invention will become apparent from the following description of the preferred embodiment taken in conjunction with the accompanying drawings.